Pump, pump device, and liquid supply system

ABSTRACT

A stay of a liquid can be suppressed. A pump 100 includes a tube 102, having elasticity, in which a liquid as a target to be delivered flows; a tube housing 104 which covers an outside of the tube 102 and keeps a gas in an inner space V between an outer surface of the tube 102 and the tube housing 104; and an electropneumatic regulator RE configured to supply the gas into the inner space V and discharge the gas from the inner space V.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Japanese Patent Application Nos.2014-216312 and 2015-144946 filed on Oct. 23, 2014 and Jul. 22, 2015,respectively, the disclosures of which are incorporated herein byreference.

TECHNICAL FIELD

The embodiments described herein pertain generally to a pump, a pumpdevice, and a liquid supply system.

BACKGROUND

Patent Documents 1 and 2 describe that in the case of performing amicroprocessing on a substrate (for example, a semiconductor substrate),a liquid supply system is used to supply a liquid onto a surface of thesubstrate from a nozzle. A liquid supply system described in PatentDocument 1 employs a bellows pump in order to deliver a liquid. A liquidsupply system described in Patent Document 2 employs a diaphragm pump inorder to deliver a liquid.

Patent Document 1: Japanese Patent Laid-open Publication No. 2008-305980

Patent Document 2: Japanese Patent Laid-open Publication No. 2012-151197

SUMMARY

A bellows pump includes a bellows-shaped bellows in order to suck anddischarge a liquid. In a bellows portion of the bellows, when thebellows pump is operated, a thin film member constituting the bellows isfolded. For this reason, a narrow space is formed in the vicinity of thebellows portion. As for a diaphragm pump, a thin film having flexibilityis provided in a main body in order to suck and discharge a liquid. Thethin film becomes closer to the main body when the diaphragm pump isoperated. For this reason, a narrow space is also formed in the vicinityof a place where the thin film and the main body are in contact witheach other. Therefore, it is easy for a liquid to stay in such narrowspaces.

Generally, a liquid may contain foreign materials such as particles(fine particles). For this reason, if the liquid stays in the narrowspace as described above, a concentration of the particles in the liquidis increased. If the liquid with the high concentration of the particlesis discharged from a nozzle to a substrate, many particles are attachedto the substrate, which may cause defects in the processed substrate.

Therefore, a pump, a pump device, and a liquid supply system capable ofsuppressing a liquid from staying are described in the presentdisclosure.

In one exemplary embodiment, a pump includes a tube, having elasticity,in which a liquid as a target to be delivered flows; a tube housingwhich covers an outside of the tube and keeps a gas in an inner spacebetween an outer surface of the tube and the tube housing; and asupply/discharge unit configured to supply the gas into the inner spaceand discharge the gas from the inner space.

In the pump, by supplying or discharging a gas into/from the inner spacethrough the supply/discharge unit, a pressure around the tube isincreased or decreased. For this reason, when the pressure around thetube is increased, the tube is crushed, so that the liquid within thetube is pushed out of the tube. Meanwhile, when the pressure around thetube is decreased, the tube is expanded and the inside of the tube isfilled with the liquid. As compared with a bellows pump or a diaphragmpump, the tube has fewer narrow spaces where it is easy for the liquidto stay. Accordingly, it is possible to suppress the stay of the liquid.Therefore, a concentration of particles in the liquid is not easilyincreased. Further, in the pump, a gas pressure is applied to the tubein order to deliver the liquid. For this reason, as compared with a casewhere a liquid pressure is applied to the tube, a configuration can befurther simplified.

The tube may include recessed grooves which are extended along a centralaxis of the tube and recessed toward the central axis. In this case, aportion of the tube in the vicinity of the recessed grooves is easilydeformed. Therefore, if the pressure around the tube is increased ordecreased, the portion of the tube in the vicinity of the recessedgrooves is crushed or expanded in a radial direction of the tube priorto the other portions. For this reason, in the tube including therecessed grooves, the tube is likely to be continuously deformed in thevicinity of the recessed grooves according to a gas pressure around thetube, so that it is possible to suppress a sudden deformation of thetube.

The tube may be extended to penetrate the tube housing, and a portion ofthe tube including the recessed grooves may be positioned within thetube housing. If the tube does not penetrate the tube housing, aconnecting member for connecting the tube to another liquid deliveryline is required to be provided at an inlet/outlet opening of the tubehousing. Therefore, a narrow space may be formed in the connectingmember. However, if the tube is extended to penetrate the tube housing,the connecting member is not needed and such a narrow space is noteasily formed. Therefore, it is possible to further suppress the stay ofthe liquid.

The tube may include three recessed grooves, and the three recessedgrooves may be arranged to be approximately equi-spaced in acircumferential direction of the tube. In this case, recessed portionsand protruded portions are alternately arranged to be approximatelyequi-spaced along the circumferential direction of the tube. For thisreason, if the pressure around the tube is increased, the tube isapproximately uniformly crushed in the circumferential direction of thetube. Therefore, it is difficult for the tube to be locally and severelydeformed, so that an excessive stress is not easily applied to the tube.Further, since the tube includes the three recessed grooves, it ispossible to scale down the tube while securing a deformation amount ofthe tube. Furthermore, since the tube includes the three recessedgrooves, the tube is likely to be continuously deformed according to thegas pressure around the tube, so that a sudden deformation of the tubeis not easily generated. Therefore, it is possible to stably control astatus of the tube.

In another exemplary embodiment, a pump device includes theabove-described pump; and a housing including a main part and anextension part which has a smaller thickness than the main part and isextended outwardly from the main part. Here, the main part accommodatesthe supply/discharge unit, and the extension part accommodates the tubeand the tube housing.

The pump device has the same operation and effect as the above-describedpump. Meanwhile, it is assumed that if two pump devices are used, thetwo pump devices are assembled and configured as a pair or a set of pumpdevices. Herein, the pair of pump devices may have a large volumedepending on an assembling method of the two pump devices. However, asfor the pump device, the extension part of the housing accommodates thetube and the tube housing therein. For this reason, in a state where themain parts of the two pump devices are not overlapped with each other,it is possible to scale down the pair of pump devices as a whole with asmall thickness of the pair of pump devices by overlapping the extensionparts having small thicknesses are overlapped with each other, thoughthe entire length of the assembled pump devices.

In yet another exemplary embodiment, a liquid supply system includes theabove-described pump; a first liquid delivery line connecting the pumpto a liquid source; a second liquid delivery line connecting the pump toa nozzle through which a liquid is discharged; and a third liquiddelivery line extended with the pump. Further at least a portion of thethird liquid delivery line is constituted by the tube.

The liquid supply system has the same operation and effect as theabove-described pump.

The liquid supply system may further include a filter provided on thefirst liquid delivery line; and an assist pump provided on the firstliquid delivery line between the filter and the liquid source. If thefilter is provided on the first liquid delivery line, the filter isarranged at an upstream side of the pump. Further, there is a pressureloss between an inlet side and an outlet side of the filter. As aresult, depending on a viscosity of the liquid, the liquid may be foamedor a discharge amount of the liquid from the pump may be decreased dueto lack of suction force of the pump. However, since the assist pump isprovided on the first liquid delivery line between the filter and liquidsource, the liquid to which a pressure by the assist pump is applied canbe delivered to the filter or the pump at a downstream side. For thisreason, the liquid is likely to have a positive pressure at thedownstream side of the assist pump. Therefore, even if a pressure of theliquid is decreased at the downstream side of the filter due to thepressure loss, the liquid is likely to have a positive pressure at thedownstream side of the filter. As a result, even if the liquid has amiddle or high viscosity, it is possible to suppress the dischargeamount of the liquid from the pump from being decreased or the liquidfrom being foamed while removing the foreign materials in the liquidwith the filter.

An inlet opening of the assist pump for the liquid and a dischargeopening of the liquid source for the liquid may be formed as one body.When the assist pump is operated, a pressure at an upstream side of thepump may be decreased and a negative pressure may be generated, so thatthe liquid may be foamed. However, in this case, since the inlet openingof the assist pump and the discharge opening of the liquid source areformed as one body and thus very close to each other, a space where anegative pressure can be generated is not formed. Therefore, it ispossible to further suppress the liquid from being foamed.

According to the above-described pump, pump device and liquid supplysystem, it is possible to suppress the stay of a liquid.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects, embodiments,and features described above, further aspects, embodiments, and featureswill become apparent by reference to the drawings and the followingdetailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

In the detailed description that follows, embodiments are described asillustrations only since various changes and modifications will becomeapparent to those skilled in the art from the following detaileddescription. The use of the same reference numbers in different figuresindicates similar or identical items.

FIG. 1 is a perspective view illustrating a substrate processing system;

FIG. 2 is a cross-sectional view taken along a line II-II of FIG. 1;

FIG. 3 is a cross-sectional view taken along a line III-III of FIG. 2;

FIG. 4 is a schematic diagram illustrating a coating unit;

FIG. 5 is a diagram illustrating a liquid supply system;

FIG. 6 is a diagram schematically illustrating a cross section of apump;

FIG. 7A is a side view illustrating a tube, and FIG. 7B is across-sectional view taken along a line B-B of FIG. 7A;

FIG. 8 is a perspective view illustrating a pump device;

FIG. 9 is a diagram describing an operation of the liquid supply systemwhen discharging a liquid;

FIG. 10 is a cross-sectional view illustrating a crushed shape of atube;

FIG. 11 is a perspective view illustrating a pair of pump devices;

FIG. 12 is a diagram illustrating a liquid supply system in accordancewith another exemplary embodiment;

FIG. 13 is a timing chart for describing operations of a pump and anassist pump; and

FIG. 14 is a cross-sectional view illustrating mainly an assist pumpaccording to another example.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part of the description. In thedrawings, similar symbols typically identify similar components, unlesscontext dictates otherwise. Furthermore, unless otherwise noted, thedescription of each successive drawing may reference features from oneor more of the previous drawings to provide clearer context and a moresubstantive explanation of the current exemplary embodiment. Still, theexemplary embodiments described in the detailed description, drawings,and claims are not meant to be limiting. Other embodiments may beutilized, and other changes may be made, without departing from thespirit or scope of the subject matter presented herein. It will bereadily understood that the aspects of the present disclosure, asgenerally described herein and illustrated in the drawings, may bearranged, substituted, combined, separated, and designed in a widevariety of different configurations, all of which are explicitlycontemplated herein.

<Configuration of Substrate Processing System>

A substrate processing system 1 includes a coating and developing device2 and an exposure device 3. The exposure device 3 is configured toperform an exposure process on a resist film. To be specific, theexposure device 3 is configured to irradiate an energy line to a portionas an exposure target in the resist film (photosensitive film) byimmersion lithography or the like. The energy line may include, forexample, an ArF excimer laser, a KrF excimer laser, a g-ray, an i-ray,or an extreme ultraviolet (EUV) ray.

The coating and developing device 2 is configured to form a resist filmon a surface of a wafer W (substrate) before the exposure process by theexposure device 3, and also perform a developing process of the resistfilm after the exposure process. In the present exemplary embodiment,the wafer W has a circular plate shape. However, there may be used awafer having a circular shape of which a part is notched or having otherpolygonal shapes instead of the circular shape. The wafer W may include,for example, a semiconductor substrate, a glass substrate, a masksubstrate, an FPD (Flat Panel Display) substrate, and various othersubstrates.

As illustrated in FIG. 1 to FIG. 3, the coating and developing device 2includes a carrier block 4, a processing block 5, and an interface block6. The carrier block 4, the processing block 5, and the interface block6 are arranged in a horizontal direction.

The carrier block 4 includes a carrier station 12 and a carry-in/outunit 13. The carrier station 12 is configured to support multiplecarriers 11. The carrier 11 is configured to accommodate, for example,multiple wafers W in a sealing state, and includes an opening/closingdoor (not illustrated) for carrying in/out the wafer W at its sidesurface 11 a (see FIG. 3). The carrier 11 is detachably provided on thecarrier station 12 such that the side surface 11 a is in contact with aside of the carry-in/out unit 13.

The carry-in/out unit 13 is positioned between the carrier station 12and the processing block 5. The carry-in/out unit 13 includes multipleopening/closing doors 13 a respectively corresponding to the multiplecarriers 11 on the carrier station 12. By opening the opening/closingdoor on the side surface 11 a and the opening/closing doors 13 a at thesame time, the inside of the carrier 11 communicates with the inside ofthe carry-in/out unit 13. A delivery arm A1 is provided in thecarry-in/out unit 13. The delivery arm A1 is configured to take out thewafer W from the carrier 11, deliver the wafer W to the processing block5, receive the wafer W from the processing block 5, and return the waferW to the inside of the carrier 11.

The processing block 5 includes a BCT module 14, a COT module 15, a TCTmodule 16, and a DEV module 17. The BCT module 14 is a module forforming a lower film. The COT module 15 is a module for forming a resistfilm. The TCT module 16 is a module for forming an upper film. The DEVmodule 17 is a module for performing the developing process. The DEVmodule 17, the BCT module 14, the COT module 15, and the TCT module 16are arranged in sequence from a bottom surface side.

The BCT module 14 is configured to form the lower film on the surface ofthe wafer W. Multiple coating units (not illustrated), multiple heattreatment units (not illustrated), and a delivery arm A2 configured todeliver the wafer W to these units are provided in the BCT module 14.The coating unit is configured to coat a coating liquid for forming thelower film on the surface of the wafer W. The heat treatment unit isconfigured to perform a heat treatment by heating the wafer W with, forexample, a heating plate, and cooling the heated wafer W with, forexample, a cooling plate. A specific example of the heat treatment to beperformed in the BCT module 14 may include a heating process for formingthe lower film by hardening the coating liquid.

The COT module 15 is configured to form the thermosetting orphotosensitive resist film on the lower film. Multiple coating units U1,multiple heat treatment units U2, and a delivery arm A3 configured todeliver the wafer W to these units are provided in the COT module 15(see FIG. 2 and FIG. 3). The coating unit U1 is configured to coat aprocessing liquid (resist liquid) for forming the resist film on thelower film. The heat treatment unit U2 is configured to perform the heattreatment by heating the wafer W with, for example, a heating plate, andcooling the heated wafer W with, for example, a cooling plate. Aspecific example of the heat treatment to be performed in the COT module15 may include a heating (PAB: Pre Applied Bake) process for forming theresist film by hardening the coating liquid.

The TCT module 16 is configured to form the upper film on the resistfilm. Multiple coating units (not illustrated), multiple heat treatmentunits (not illustrated), and a delivery arm A4 configured to deliver thewafer W to these units are provided in the TCT module 16. The coatingunit is configured to coat a coating liquid for forming the upper filmon the surface of the wafer W. The heat treatment unit is configured toperform the heat treatment by heating the wafer W with, for example, aheating plate, and cooling the heated wafer W with, for example, acooling plate. A specific example of the heat treatment to be performedin the TCT module 16 may include a heating process for forming the upperfilm by hardening the coating liquid.

The DEV module 17 is configured to perform the developing process on anexposed resist film. Multiple developing units (not illustrated),multiple heat treatment units (not illustrated), a delivery arm A5configured to deliver the wafer W to these units, and a direct deliveryarm A6 configured to deliver the wafer W without passing through theseunits are provided in the DEV module 17. The developing unit isconfigured to form a resist pattern by partially removing the resistfilm. The heat treatment unit is configured to perform the heattreatment by heating the wafer W with, for example, a heating plate, andcooling the heated wafer W with, for example, a cooling plate. Aspecific example of the heat treatment to be performed in the DEV module17 may include a heating (PEB: Post Exposure Bake) process performedbefore the developing process and a heating (PB: Post Bake) processperformed after the developing process.

A shelf unit U10 is prepared within the processing block 5 at a side ofthe carrier block 4 (see FIG. 2 and FIG. 3). The shelf unit U10 isprovided to reach the TCT module 16 from a bottom surface and the shelfunit U10 includes multiple cells which are vertically arranged. Anelevation arm A7 is provided in the vicinity of the shelf unit U10. Theelevation arm A7 is configured to move up and down the wafer W betweenthe cells of the shelf unit U10.

A shelf unit U11 is prepared within the processing block 5 at a side ofthe interface block 6 (see FIG. 2 and FIG. 3). The shelf unit U11 isprovided to reach an upper portion of the DEV module 17 from the bottomsurface and the shelf unit U10 includes multiple cells which arevertically arranged.

A delivery arm A8 is provided in the interface block 6, and theinterface block 6 is connected to the exposure device 3. The deliveryarm A8 is configured to take out the wafer W from the shelf unit U11,deliver the wafer W to the exposure device 3, receive the wafer W fromthe exposure device 3, and return the wafer W to the shelf unit U11.

<Configuration of Coating Unit>

Hereinafter, the coating unit (coating device) U1 will be described inmore detail with reference to FIG. 4. As illustrated in FIG. 4, thecoating unit U1 includes a rotational holding unit 20, a driving unit30, a pump device 200, and a control unit 50.

The rotational holding unit 20 includes a rotation unit 21 and a holdingunit 23. The rotation unit 21 includes a shaft 22 which is upwardlyprotruded. The rotation unit 21 is configured to rotate the shaft 22using, for example, an electric motor as a power source. The holdingunit 23 is provided at a tip end portion of the shaft 22. The wafer W isplaced on the holding unit 23. The holding unit 23 is configured to holdthe wafer W in a substantially horizontal posture by, for example, theattraction or the like. That is, the rotational holding unit 20 isconfigured to rotate the wafer W around an axis (rotation axis)perpendicular to the surface of the wafer W while the wafer W is in asubstantially horizontal posture. In the present exemplary embodiment,the rotation axis passes through the center of the wafer W having acircular shape and thus serves as a central axis. In the presentexemplary embodiment, the rotational holding unit 20 is configured torotate the wafer W clockwise when viewed from the top, as illustrated inFIG. 4.

The driving unit 30 is configured to drive a nozzle N. The driving unit30 includes a guide rail 31, a sliding block 32, and an arm 33. Theguide rail 31 is extended in a horizontal direction above the rotationalholding unit 20 (wafer W). The sliding block 32 is connected to theguide rail 31 such that the sliding block 32 can be moved in thehorizontal direction along the guide rail 31. The arm 33 is connected tothe sliding block 32 such that the arm 33 can be moved in a verticaldirection. The nozzle N is connected to a lower end of the arm 33.

The driving unit 30 is configured to move the sliding block 32 and thearm 33 using, for example, an electric motor as a power source (notillustrated) and move the nozzle N accordingly. When viewed from thetop, the nozzle N is moved along a radial direction of the wafer W on astraight line orthogonal to the rotation axis of the wafer W whiledischarging the coating liquid.

The pump device 200 is configured to deliver the coating liquid to thenozzle N from a liquid source (for example, a liquid bottle B or aliquid tank T1 to be described later) and discharge the coating liquidfrom the nozzle N to a surface Wa of the wafer W in response to acontrol signal from the control unit 50. To be described in detaillater, the pump device 200, the nozzle N, and the liquid source arecomponents of the liquid supply system 40 for supplying the coatingliquid to a target object (the wafer W in the present exemplaryembodiment).

The nozzle N is downwardly opened toward the surface Wa of the wafer W.The coating liquid is a liquid used for forming a coating film R (seeFIG. 4) on the surface Wa of the wafer W. Examples of the coating liquidmay include a resist liquid for forming a resist pattern or a liquid forforming an anti-reflection film (for example, a bottom anti-reflectioncoating (BARC) film and a silicon-containing anti-reflection coating(SiARC) film). When a processing liquid dicharged to the surface Wa ofthe wafer W is dried, the coating film R is formed on the surface Wa ofthe wafer W, as illustrated in FIG. 4.

The control unit 50 is configured of one or more control computers, andis configured to control the coating unit U1. The control unit 50includes a display unit (not illustrated) configured to display acontrol condition setting screen, an input unit (not illustrated)configured to input a control condition, and a reading unit (notillustrated) configured to read a program from a computer-readablestorage medium. The storage medium stores therein a program forexecuting the coating process in the coating unit U1. The program isread by the reading unit of the control unit 50. The storage medium maybe, for example, a semiconductor memory, an optical recording disc, amagnetic recording disc, or a magneto-optical recording disc. Thecontrol unit 50 is configured to control the coating unit U1 accordingto the control condition inputted to the input unit and the program readby the reading unit and execute a coating process in the coating unitU1.

<Configuration of Liquid Supply System>

A configuration of the liquid supply system 40 will be described withreference to FIG. 5. As illustrated in FIG. 5, the liquid supply system40 includes the liquid bottle B, liquid tanks T1 and T2, a pump 100, afilter device F, lines (liquid delivery lines) D1 to D6, valves V1 toV7, pressure sensors (pressure measurement units) PS1 and PS2, a nozzleN, and a control unit C.

An upstream end of the line D1 is connected to a N₂ gas source. Adownstream end of the line D1 is connected to a top lid portion of theliquid bottle B such that the downstream end of the line D1 ispositioned in the vicinity of a top lid of the liquid bottle B. Theliquid bottle B serves as a supply source (liquid source) for supplyingthe coating liquid to the nozzle N. The valve V1 is provided on the lineD1. The valve V1 is an air operation valve configured to open/close(turn on/off) a valve using air.

An upstream end of the line D2 is connected to the top lid portion ofthe liquid bottle B such that the upstream end of the line D2 ispositioned in the vicinity of a bottom of the liquid bottle B. Adownstream end of the line D2 is connected to a top lid portion of theliquid tank T1 such that the downstream end of the line D2 is positionedin the vicinity of a top lid of the liquid tank T1. The liquid tank T1serves as a storage tank configured to temporarily store the coatingliquid discharged from the liquid bottle B, and also serves as a supplysource (liquid source) for supplying the coating liquid to the nozzle N.

An upstream end of the line D3 is connected to a bottom portion of theliquid tank T1. A downstream end of the line D3 is connected to thenozzle N. The valve V2, the filter device F, the liquid tank T2, thevalve V3, the pump 100, the pressure sensor PS1, the valve V4, and thevalve V5 are provided on the line D3 in sequence from an upstream sidethereof.

The valves V2 to V5 are the same air operation valves as the valve V1.The valve V5 may have a function (flow rate control function) ofcontrolling a flow rate of a coating liquid discharged from the nozzle Nto a predetermined level. The valve V5 may have a function (suck backfunction) of sucking the coating liquid within the nozzle N such thatthe coating liquid cannot remain in the nozzle N when the discharging ofthe coating liquid from the nozzle N is stopped.

In the filter device F, a filter configured to remove foreign materialssuch as particles contained in the coating liquid is provided within ahousing. In the liquid tank T2, bubbles remaining within the coatingliquid discharged from an outlet of the filter device F are removed.Although will be described in detail later, the pump 100 is configuredto suck the coating liquid within the liquid tank T2 and deliver thecoating liquid toward the nozzle N. The pressure sensor PS1 isconfigured to measure a pressure (liquid pressure) of the coating liquidflowing in the pump 100 (the tube 102 to be described later). Thepressure sensor PS1 is configured to output a signal indicating a valueof the measured liquid pressure to the control unit C.

An upstream end of the line D4 is connected to an exhaust port of thefilter device F. A downstream end of the line D4 is connected to theoutside of the system. For this reason, a gas separated from the coatingliquid when the coating liquid passes through the filter device F isdischarged to the outside of the system through the line D4. The valveV6 is provided on the line D4. The valve V6 is the same air operationvalve as the valve V1.

An upstream end of the line D5 is connected to an exhaust port of theliquid tank T2. A downstream end of the line D5 is connected to the lineD4 at a downstream side of the valve V6. For this reason, a gasseparated from the coating liquid in the liquid tank T2 is discharged tothe outside of the system through the line D5. The valve V7 is providedon the line D5. The valve V7 is the same air operation valve as thevalve V1.

One end of the line D6 is connected to the pump 100 (a tube housing 104to be described later). The other end of the line D6 is connected to anelectropneumatic regulator (supply/discharge unit) RE. Theelectropneumatic regulator RE includes an electromagnetic valveconfigured to perform an opening/closing operation in response to acontrol signal from the control unit C. The electropneumatic regulatorRE is configured to suck air from an air source or discharge air to theoutside according to an opening degree of the electromagnetic valve.Thus, the electropneumatic regulator RE is configured to adjust an airpressure (a gas pressure) within the pump 100 (within an inner space Vto be described later). The pressure sensor PS2 is provided on the lineD6. The pressure sensor PS2 is configured to measure the air pressure(the gas pressure) within the pump 100 (within the inner space V to bedescribed later). The pressure sensor PS2 is configured to output asignal indicating a value of the measured gas pressure to the controlunit C.

The control unit C is configured of one or more control computers, andis configured to control the electropneumatic regulator RE. The controlunit C includes a display unit (not illustrated) configured to display acontrol condition setting screen, an input unit (not illustrated)configured to input a control condition, and a reading unit (notillustrated) configured to read a program from a computer-readablestorage medium. The storage medium stores therein a program forexecuting the liquid delivery process in the pump 100. The program isread by the reading unit of the control unit C. The storage medium maybe, for example, a semiconductor memory, an optical recording disc, amagnetic recording disc, or a magneto-optical recording disc. Thecontrol unit C is configured to control the electropneumatic regulatorRE according to the control condition inputted to the input unit and theprogram read by the reading unit and execute a liquid delivery processin the pump 100.

<Configuration of Pump>

Hereinafter, a configuration of the pump 100 will be described withreference to FIG. 6 to FIG. 7B. As illustrated in FIG. 6, the pump 100includes the tube 102, the tube housing 104, and the above-describedelectropneumatic regulator RE.

The tube 102 has flexibility and elasticity. That is, the tube 102 has aproperty of returning to its original shape when an external force isapplied to the tube 102 from the inside or the outside. The tube 102 maybe formed of, for example, fluorine resin. One end of the tube 102 isconnected to the valve V3 (see FIG. 5). The other end of the tube 102 isconnected to the pressure sensor PS1 (see FIG. 5). That is, the tube 102constitutes a part of the line D3. The tube 102 includes a thick portion102 a and a thin portion 102 b, as illustrated in FIG. 6 to FIG. 7B.

The thick portion 102 a has a cylindrical shape. An outer diameter ofthe thick portion 102 a may be, for example, about 12.7 mm. An innerdiameter of the thick portion 102 a may be, for example, about 9.5 mm. Awall thickness of the thick portion 102 a may be, for example, about 1.6mm.

The thin portion 102 b is extended between a pair of thick portions 102a. That is, both ends of the thin portion 102 b are respectivelyconnected to the thick portions 102 a. A wall thickness of the thinportion 102 b may be, for example, about 0.2 mm.

As illustrated in FIG. 7A and FIG. 7B, the thin portion 102 b includes arecessed groove 102 c. The recessed groove 102 c is extended along acentral axis of the tube 102 (an extension direction of the tube 102).The recessed groove 102 c is recessed toward the central axis of thetube 102 (an inside of the tube 102). The thin portion 102 b (tube 102)may include multiple recessed grooves 102 c. In the present exemplaryembodiment, the thin portion 102 b (tube 102) includes three recessedgrooves 102 c. The three recessed grooves 102 c are arranged to beapproximately equi-spaced along a circumferential direction of the tube102, as illustrated in FIG. 7B. That is, in the thin portion 102 b ofthe present exemplary embodiment, recessed portions and protrudedportions are alternately arranged to be approximately equi-spaced alongits circumferential direction.

Returning to FIG. 6, the tube housing 104 has a cylindrical shape. Thetube housing 104 accommodates a part of the tube 102 such that the tubehousing 104 covers the outside of the tube 102. The tube housing 104 isextended coaxially with respect to the tube 102 along the central axisof the tube 102 (the extension direction of the tube 102). In otherwords, the tube 102 penetrates the tube housing 104. The thin portion102 b of the tube 102 is positioned within the tube housing 104. Theinner space V, in which a gas (air) is kept, is formed between an outersurface of the tube 102 and the tube housing 104. One end of the line D6is connected to the tube housing 104. Thus, the supply of the gas intothe inner space V and the discharge of the gas from the inner space Vare performed by the electropneumatic regulator RE.

<Pump Device>

In the present exemplary embodiment, some components constituting theabove-described liquid supply system 40 also constitute the liquiddelivery system 60, as illustrated in FIG. 5. Component constituting theliquid delivery system 60 may include, for example, the pump 100, thefilter device F, the control unit C, the pressure sensors PS1 and PS2,the liquid tank T2, the electropneumatic regulator RE, the valves V2 toV4, V6, and V7, a part of the line D3, and the lines D4 and D5. The pumpdevice 200 includes a housing 202 illustrated in FIG. 8 and thecomponents constituting the liquid delivery system 60.

The housing 202 includes a main part 202 a and an extension part 202 bas illustrated in FIG. 8. The main part 202 a and the extension part 202b are configured as one body. The main part 202 a has a hexahedralshape. The main part 202 a includes a pair of main surfaces S1 eachhaving a relatively greater area than the other surfaces; a pair of sidesurfaces S2; and a pair of end surfaces S3. The main part 202 aaccommodates at least the filter device F, the control unit C, thepressure sensors PS1 and PS2, the liquid tank T2, and theelectropneumatic regulator RE among the components constituting theliquid delivery system 60.

The extension part 202 b is extended in a linear shape from the sidesurface S2 of the main part 202 a toward the outside. An extensiondirection of the extension part 202 b corresponds to a facing directionof the pair of side surfaces S2 in the present exemplary embodiment.However, the extension direction of the extension part 202 b is notlimited thereto, and may correspond to a direction intersecting ororthogonal to a facing direction of the pair of main surfaces S1. Athickness of the extension part 202 b in the facing direction of themain surfaces S1 is smaller than a thickness of the main part 202 a inthe same facing direction. The extension part 202 b accommodates atleast the pump 100 among the components constituting the liquid deliverysystem 60. The pump 100 is arranged within the extension part 202 b andextended along the extension direction of the extension part 202 b.

On the end surface S3 of the main part 202 a, connecting members 204 ato 204 e are provided. The connecting member 204 a is connected, outsidethe pump device 200, to a line on at upstream side of the pump device200 (a part of the lines D1, D2, and the line D3 positioned at theupstream side of the pump device 200). The line positioned at theupstream side constitutes an upstream-side liquid delivery line (firstliquid delivery line) connecting the liquid bottle B to the pump device200. For this reason, the coating liquid from the liquid tank T1 isintroduced into the pump device 200 through the connecting member 204 a.

The connecting member 204 b is connected, outside the pump device 200,to a line at a downstream side of the pump device 200 (a part of theline D3 positioned at the downstream side of the pump device 200). Theline positioned at the downstream side constitutes a downstream-sideliquid delivery line (second liquid delivery line) connecting the pumpdevice 200 to the nozzle N.

In the pump device 200, the line (a part of the line D3) extendedbetween the connecting member 204 a and the connecting member 204 bconstitutes a liquid delivery line (third liquid delivery line) extendedwithin the pump device 200. That is, the connecting member 204 a and theconnecting member 204 b are connected, inside the pump device 200, tothe liquid delivery line extended within the pump device 200. A part ofthe corresponding liquid delivery line is configured of the tube 102.For this reason, the coating liquid delivered from the pump 100 towardthe downstream side (the nozzle N side) is discharged to the outside ofthe pump device 200 through the connecting member 204 b.

The connecting member 204 c is connected, outside the pump device 200,to the outside of the system via a non-illustrated line. The connectingmember 204 c is connected, inside the pump device 200, to the downstreamend of the line D4. For this reason, a gas within the filter device F ora gas within the liquid tank T2 is discharged to the outside of the pumpdevice 200 through the lines D4 and D5 and the connecting member 204 c.

The connecting member 204 d is connected, outside the pump device 200,to an air source via a non-illustrated line. The connecting member 204 eis connected, outside the pump device 200, to the outside of the systemvia a non-illustrated line. Each of the connecting members 204 d and 204e is connected, inside the pump device 200, to the electropneumaticregulator RE via a non-illustrated line. For this reason, air from theair source is introduced into the electropneumatic regulator RE throughthe connecting member 204 d. The air within the electropneumaticregulator RE is discharged to the outside of the electropneumaticregulator RE (the outside of the pump device 200) through the connectingmember 204 e.

<Operation of Liquid Supply System>

Hereinafter, an operation of the liquid supply system 40 (a dischargeoperation of discharging a coating liquid from the nozzle N) will bedescribed with reference to FIG. 9 and FIG. 10. While the inside of thetube 102 is filled with the coating liquid, the control unit C closesthe valves V1 to V3, V6, and V7 and opens the valves V4 and V5, and alsooperates the electropneumatic regulator RE to supply air into the innerspace V. Thus, a pressure within the inner space V is increased, and thethin portion 102 b of the tube 102 positioned within the inner space Vis crushed by an air pressure. When the tube 102 (the thin portion 102b) is crushed, the recessed grooves 102 c of the tube 102 (the thinportion 102 b) become closer to each other or are brought into contactwith each other, as illustrated in FIG. 10. Thus, the volume within thetube 102 (the thin portion 102 b) is decreased, and the coating liquidwithin the tube 102 is pushed toward the opened valves V4 and V5. As aresult, if the nozzle N is positioned above the wafer W, the coatingliquid is discharged from the nozzle N toward the surface Wa of thewafer W.

<Operation Effect>

In the present exemplary embodiment described above, theelectropneumatic regulator RE supplies and discharges a gas into/fromthe inner space V to increase and decrease the pressure around the tube102. For this reason, when the pressure around the tube 102 isincreased, the tube 102 is crushed and the coating liquid (liquid)within the tube 102 is pushed out of the tube 102. Meanwhile, when thepressure around the tube 102 is decreased, the tube 102 is expanded andthe inside of the tube 102 is filled with the coating liquid. Ascompared with a bellows pump or a diaphragm pump, the tube 102 has asmall narrow space where it is easy for the coating liquid to stay. Forthis reason, it is possible to suppress the stay of the coating liquid.Therefore, a concentration of particles in the coating liquid is noteasily increased. Further, in the present exemplary embodiment, the airpressure is applied to the tube 102 in order to deliver the coatingliquid. For this reason, as compared with the case where the liquidpressure is applied to the tube 102, a configuration can be simplified.

In the present exemplary embodiment, the tube 102 includes the recessedgrooves 102 c which are extended along the central axis and recessedtoward the central axis. With the recessed grooves 102 c, the vicinityof the recessed grooves 102 c in the tube 102 is easily deformed.Therefore, if the pressure around the tube 102 is increased ordecreased, the vicinity of the recessed grooves 102 c is crushed orexpanded in the radial direction of the tube 102 more easily than theother portions. As such, in the tube 102 including the recessed grooves102 c, the tube 102 is likely to be continuously deformed in thevicinity of the recessed grooves 102 c according to the air pressurearound the tube 102, and, thus, it is possible to suppress a suddendeformation of the tube 102.

However, if the tube 102 does not penetrate the tube housing 104,connecting members for connecting the tube 102 to another liquiddelivery line may be needed at inlet/outlet openings of the tube housing104. For this reason, there may be a narrow space in the connectingmember. However, in the present exemplary embodiment, the tube 102 isextended to penetrate the tube housing 104 and the thin portion 102 b ofthe tube 102 is positioned within the tube housing 104. As a result, theabove-described connecting member is not needed, and a joint portion forthe tube 102 is not formed at a boundary between the inside and theoutside of the tube housing 104. Therefore, a narrow space is not easilyformed in the tube 102 and in the liquid delivery line constituted, atleast in part, by the tube 102. Therefore, it is possible to furthersuppress the stay of the coating liquid.

In the present exemplary embodiment, the tube 102 includes the threerecessed grooves 102 c and the three recessed grooves 102 c are arrangedto be approximately equi-spaced along the circumferential direction ofthe tube 102. For this reason, if the pressure around the tube 102 isincreased, the tube 102 is approximately uniformly crushed in thecircumferential direction of the tube 102. Therefore, it is difficultfor the tube 102 to be locally and severely deformed, so that anexcessive stress is not easily applied to the tube 102. Further, sincethe tube 102 includes the three recessed grooves 102 c, it is possibleto scale down the tube 102 while securing the deformation amount of thetube 102. Furthermore, if the tube 102 includes two recessed grooves 102c or less, when the pressure around the tube 102 is increased, the wallsof the tube 102 are entirely brought into contact with each other, sothat it becomes difficult to control the liquid delivery flow rate. Ifthe tube 102 includes four recessed grooves 102 c or more, it isdifficult for the tube 102 to be crushed, and, thus, the tube 102 may bescaled up to solve such a problem.

In the present exemplary embodiment, the inner space V between the tubehousing 104 covering the outside of the tube 102 and the outer surfaceof the tube 102 is filled with air (gas). That is, the air is used as aworking fluid for operating the tube 102. For this reason, a mechanismfor supplying the air into the inner space V and discharging the airfrom the inner space V is needed, but a relatively complicated drivingmechanism such as a piston or a motor may not be used. Therefore, it ispossible to deliver the liquid with a simple configuration.

Another Exemplary Embodiment

Although the exemplary embodiment has been described in detail, variousmodifications and changes may be added to the above-described exemplaryembodiment within the scope of the present disclosure. By way ofexample, two pump devices 200 may be combined and used as a pair or aset of pump devices. Herein, a volume of the pair of pump devices may beincreased depending on a method of assembling two pump devices.Therefore, as illustrated in FIG. 11, in a state where the main parts202 a of the two pump devices 200 are not overlapped with each other, apair of pump devices may be assembled by overlapping the extension part202 b of one pump device 200 with the extension part 202 b of the otherpump device 200. In this case, though the entire length of the assembledpump devices is increased, the extension parts 202 b having smallthicknesses are overlapped with each other. For this reason, it ispossible to scale down the pair of pump devices as a whole with a smallthickness of the pair of pump devices.

Although the air is supplied into the inner space V by theelectropneumatic regulator RE in the present exemplary embodiment, anygas (for example, a nitrogen gas or an inert gas having low chemicalreactivity) may be used instead of the air.

Although the present disclosure is applied to the coating unit U1included in the COT module 15 in the present exemplary embodiment, thepresent disclosure may be applied to another unit instead of the coatingunit U1.

The control unit 50 may serve as the control unit C, or the control unitC may serve as the control unit 50.

An assist pump 300 may be provided on the line D3 between the liquidsource (the liquid bottle B or the liquid tank T1) and the filter deviceF. Since the liquid supply system 40 illustrated in FIG. 12 includes theliquid tank T1 positioned at a downstream side of the liquid bottle B,the assist pump 300 is positioned at a downstream side of the liquidtank T1. However, if the liquid supply system 40 does not include theliquid tank T1, the assist pump 300 may be positioned at the downstreamside of the liquid bottle B.

The assist pump 300 includes a pump unit 302 and a valve unit 304. Thepump unit 302 may employ, for example, a diaphragm pump as illustratedin FIG. 12, the pump 100 in accordance with the present exemplaryembodiment, or another kind of pump. In a case where the pump unit 302is a diaphragm pump, if the air is introduced from the air source, thediaphragm (DP) is crushed toward an inner side wall of a pump chamber302 a. As a result, the volume of the pump chamber 302 a is decreasedand the liquid within the pump chamber 302 a is discharged to theoutside thereof. Meanwhile, if the air is sucked by a vacuum source, thediaphragm (DP) is separated from the inner side wall of the pump chamber302 a. As a result, the volume of the pump chamber 302 a is increasedand the liquid is sucked into the pump chamber 302 a. The valve unit 304is the same air operation valves as the valve V1.

Hereinafter, operation timings of the pump 100 and the assist pump 300will be described with reference to FIG. 13. Firstly, at a time pointTI1, in a state where the valve V3 is closed (see (B) of FIG. 13), theinside of the inner space V is set to have a positive pressure (see (A)of FIG. 13). Thus, between the time point TI1 and a time point TI2, airis supplied into the inner space V by the electropneumatic regulator REand the coating liquid is discharged from the pump 100. At this time, inthe assist pump 300, in a state where the valve unit 304 is opened (see(D) of FIG. 13), the pump unit 302 (inside the pump chamber 302 a) isset to have a negative pressure (see (C) of FIG. 13) and the inside ofthe pump unit 302 is supplemented with the coating liquid.

After the discharge of the coating liquid from the pump 100 iscompleted, at the time point TI2, in a state where the valve V3 isopened (see (B) of FIG. 13), the inside of the inner space V is set tohave a negative pressure (see (A) of FIG. 13). Thus, between the timepoint TI2 and a time point TI3, the air is discharged from the innerspace V by the electropneumatic regulator RE and the coating liquid issucked by the pump 100. At this time, in the assist pump 300, in a statewhere the valve unit 304 is closed (see (D) of FIG. 13), the pump unit302 (inside the pump chamber 302 a) is set to have a positive pressure(see (C) of FIG. 13) and the coating liquid is discharged from the pumpunit 302.

In the example illustrated in FIG. 12, the filter device F is arrangedat an upstream side of the pump 100. Further, there is a pressure lossbetween an inlet side and an outlet side of (at a primary side and asecondary side of) the filter device F. As a result, depending on aviscosity of the coating liquid (liquid), the coating liquid may befoamed or a discharge amount of the coating liquid from the pump 100 maybe decreased due to lack of suction force of the pump 100. However, inthe example illustrated in FIG. 12, since the assist pump 300 isprovided on the line D3 between the liquid tank T1 and the filter deviceF, the coating liquid to which a pressure by the assist pump 300 isapplied can be delivered to the filter device F or the pump 100 at thedownstream side. For this reason, the coating liquid is likely to have apositive pressure at a downstream side of the assist pump 300.Therefore, even if the pressure of the coating liquid is decreased atthe downstream side of the filter device F due to the pressure loss, thecoating liquid is likely to have a positive pressure at the downstreamside of the filter device F. As a result, even if the liquid has amiddle viscosity (for example, 100 cP or more) or a high viscosity (forexample, 300 cP or more), it is possible to suppress the dischargeamount of the coating liquid from the pump 100 from being decreased orthe coating liquid from being foamed while removing the foreignmaterials in the coating liquid with the filter device F. As a result,it is possible to control an amount of the coating liquid dischargedfrom the pump 100 (nozzle N) with high accuracy. Therefore, it isparticularly applicable in the case of handling a coating liquid (aresist liquid for forming a resist pattern) with a demand for highaccuracy in a film thickness of a coating film.

Further, if the assist pump 300 is used, it is possible to suppress thecoating liquid at the downstream side of the assist pump 300 from beingfoamed. Therefore, the liquid supply system 40 (liquid delivery system60) may not include the liquid tank T2.

The assist pump 300 may be positioned at a side of the liquid sourcerather than the side of the filter device F. To be specific, a length ofa passageway (a movement distance of the coating liquid) between theliquid source and the assist pump 300 may be shorter than a length of apassageway (a movement distance of the coating liquid) between theassist pump 300 and the filter device F. As illustrated in FIG. 14, aninlet opening 300 a of the assist pump 300 for the coating liquid and adischarge opening 400 of the liquid source (the liquid bottle B or theliquid tank T1) for the coating liquid may be formed as one body. If theliquid supply system 40 includes the liquid tank T1, the liquid tank T1arranged just beside the upstream side of the assist pump 300 serves asthe liquid source for the assist pump 300. Therefore, the assist pump300 and the liquid tank T1 may be configured as one body. By way ofexample, outer wall surfaces of the assist pump 300 and the liquid tankT1 may be in direct contact with each other. If the liquid supply system40 does not include the liquid tank T1, the liquid bottle B arrangedjust beside the upstream side of the assist pump 300 serves as theliquid source for the assist pump 300. Therefore, the assist pump 300and the liquid bottle B may be configured as one body. By way ofexample, outer wall surfaces of the assist pump 300 and the liquidbottle B may be in direct contact with each other. Although the assistpump 300 and the liquid source are in direct contact with each other inthe example illustrated in FIG. 14, another member may be arrangedbetween the assist pump 300 and the liquid source and configured as onebody as a whole.

From the foregoing, it will be appreciated that various embodiments ofthe present disclosure have been described herein for purposes ofillustration, and that various modifications may be made withoutdeparting from the scope and spirit of the present disclosure.Accordingly, the various embodiments disclosed herein are not intendedto be limiting, with the true scope and spirit being indicated by thefollowing claims.

We claim:
 1. A pump device comprising: a pump including: a tube, havingelasticity, in which a liquid as a target to be delivered flows; a tubehousing which covers an outside of the tube and keeps a gas in an innerspace between an outer surface of the tube and the tube housing; and asupply/discharge unit configured to supply the gas into the inner spaceand discharge the gas from the inner space so as to increase or decreasea pressure applied onto the outer surface of the tube, a housingincluding: a main part provided with a first connecting member forintroducing the liquid into the pump device, and a second connectingmember for discharging the liquid to an outside of the pump device; andan extension part which has a smaller thickness than the main part andis extended outwardly from the main part, wherein the pump device isassembled with another pump device by overlapping the extension part ofthe pump device with another extension part of said another pump devicewithout overlapping the main part of the pump device with another mainpart of said another pump device, the main part accommodates thesupply/discharge unit, the extension part accommodates the tube and thetube housing, and the first connecting member, the second connectingmember and the tube constitute a delivery line of the liquid, and themain part is a unitary component, the main part has a hexahedral shapeincluding a pair of main surfaces, a pair of side surfaces and a pair ofend surfaces, the main surfaces have a greater area than the sidesurfaces and the end surfaces, the extension part is extended outwardlyin a linear shape from one of the side surfaces of the main part towardan outside of the main part.
 2. The pump device of claim 1, wherein thetube includes recessed grooves which are extended along a central axisof the tube and recessed toward the central axis.
 3. The pump device ofclaim 2, wherein the tube is extended to penetrate the tube housing, anda portion of the tube including the recessed grooves is positionedwithin the tube housing.
 4. The pump device of claim 2, wherein the tubeincludes three recessed grooves, and the three recessed grooves arearranged to be approximately-spaced in a circumferential direction ofthe tube.
 5. A liquid supply system comprising: the pump device asclaimed in claim 1; a first liquid delivery line connecting the pump toa liquid source; a second liquid delivery line connecting the pump to anozzle through which the liquid is discharged; and a third liquiddelivery line extended within the pump, wherein at least a portion ofthe third liquid delivery line is constituted by the tube.
 6. The liquidsupply system of claim 5, further comprising: a filter provided on thefirst liquid delivery line; and an assist pump provided on the firstliquid delivery line between the filter and the liquid source.
 7. Theliquid supply system of claim 6, wherein an inlet opening of the assistpump for the liquid and a discharge opening of the liquid source for theliquid are formed as one body.